Backyard Aquaponics
A place to discuss aquaponics

New to the board. Wondering about grow rates of catfish. Little buggers don't seem to have been growing much. Started a constant flow system about a year ago. Around 6/2011, I got some catfish and bluegill (goldfish went to neighbors and my garden). Won't get into details of system, except to say that the tank runs about 60 gallons and I have about 20 figerling-size fish in there. Feed amount depends on how much I see leftover. Judging by how much crud is on the bottom of the tank, I'm guessing they aren't really eating all that much. So if I come back the next day and there are still pellets floating around from the previous morning, I don't bother feeding them that day. Otherwise, it's usually a once-a-day feeding. Amount depends on time of year. Additionally, the system is kept outside in a greenhouse. I live in USDA zone 8. Water temp ranges from about 47F in coldest part of winter to about 87F in late summer. Plants healthy as can be. Haven't seen a sick or dead fish since just after I introduced them.

Here's my question -- is this slow-growth situation normal? The catfish are barely much bigger than the day I got them. They never really seem all that hungry (never witnessed a feeding frenzy even in summer). For the most part, they all pile on top of each other in about 1 square foot of the tank until night time when they get out and roam the tank more. In the summer (with warmer water), I see them casually sip in some pellets but otherwise, they aren't very good eaters. I had read somewhere that they can reach eatable size in about 12-18 months. Well, we're at 9 months and I'm thinking we're massively behind schedule. Any tips to get these suckers growing better? Should I be keeping the light out of the tank to encourage more movement? Thoughts?

So you say that they don't appear to be eating at all? And you have a whole load of crud on the bottom of the tank?

Get rid of anything on the bottom of your tank, thats not great for water quality. Perhaps try another feed? I don't know a lot about your catfish over there but there are a few here that have grown them successfully..

"So you say that they don't appear to be eating at all? And you have a whole load of crud on the bottom of the tank?"

No, they're just not appearing to eat much and certainly less than I'm putting in the tank (1 tbsp Nutrena floating catfish pellets per day this time of year).

Yeah, you may want to try another feed like AquaMax (by Purina Mills). I've seen it highly recommended.